A variety of benzimidazolotriazole derivatives are known such as the compounds described in U.S. Pat. Nos. 3,137,574 and 2,887,378; British Patent 851,816; J. Orq. Chem. (Journal of Organic Chemistry), Vol. 24, p. 1478-1486 (1959); JP-B49-11063 (the term "JP-B" as used herein means an "examined Japanese patent publication"); J. Heterocyclic Chem. (Journal of Heterocyclic Chemistry), Vol. 15, p. 1027-1031 (1978); and J. Orq. Chem. (Journal of Organic Chemistry), Vol. 38, p. 3084-3086 (1973). However, previously disclosed compounds are all of low in solubility in aqueous solvents which made them inconvenient to use for most practical applications.